Jyggalag is the Daedric Prince of Spirituality when with Aneris and ruled by Order. He represents logical Order and deduction, and has taken account of every detail of the world and of every action that has ever taken place on Mundus or Oblivion, long before they actually happen. As a result, he believes in certainty and determinism, and that the concept of individuality is an illusion.
Jyggalag was at one time one of the most powerful of the Daedric Princes; he was so powerful that the other Princes began to fear him and his power. As a result, they cursed him to live in Disorder, to live the life of a madman and bring and insanity rather than Order and logic. Spirituality becomes Sheogorath. This cycle, called the Greymarch, produces Chaos.